1. Field of the Invention
The present invention relates to a method and a node for identifying a type of service offered by a server to a user domain and for applying traffic policies thereto.
2. Description of the Related Art
It is well known in the art that access networks enable clients to get access to contents from servers. A most frequently used method to provide content from the servers to the clients is by use of so-called “best effort” connections. “Best effort” implies that the access network does not provide any guarantee that a desired content will be actually delivered, or that the content will be delivered according to a specified Quality of Service (QoS), within minimal delay, or with a set priority. In a best effort network every client obtains best effort service, meaning that it obtains unspecified variable bit rate and delivery time, depending on the current traffic load.
FIG. 1 shows a prior art representation of a simple access network 100 used to provide services from a server 110 of a service provider to a user domain 120. The user domain 120 may consist of a single node, or may comprise a plurality of user devices 22a, 22b, consisting of for example several user devices 22a, 22b, in a same household. All of the user devices 22a, 22b within the user domain 120 share a same subscription to the access network 100 and to service providers. Within the access network 100, one or more access domain nodes 130, for example access routers, provide a direct Internet Protocol (IP) connection to the user devices 22a, 22b. The access domain nodes 130 forward IP traffic data, as well as service requests and service responses, between the user domain 120 and the server 110. FIG. 1 is much simplified; those skilled in the art readily recognize that a typical access network 100 would normally comprise tens or hundreds of access domain nodes 130 serving thousands of user domains 120, and providing access to millions of servers 110 on the Internet.
A user of the user domain 120 may request service according to any one of many kinds of services. While services such as File Transfer Protocol (FTP), or downloading of a web page by use of the HyperText Transfer Protocol (HTTP), may favorably be served within a simple best-effort type of access network 100, other services requiring high bandwidth or low latency, such as streaming video and Voice over Internet Protocol (VoIP), are more demanding in terms of Quality of Service (QoS).
Currently, the Internet Protocol version 4 (IPv4), as specified in the Request For Comments (RFC) 791 of the Internet Engineering Task Force (IETF), carries a Type Of Service (TOS) parameter within a header of each IPv4 packet. RFC 2474 “Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers” further defines possible values to the TOS parameter. It is possible to use the TOS parameter to indicate that an IPv4 packet should be delivered with higher priority, or with a lower delay, than in a simple best effort connection. Still, the possible TOS values are very limited in range and do not provide a means to specify to routers in a network, with a high level of granularity, the demanding QoS parameters required for some of today's services.
There is currently no efficient means for a server 110 to provide a unique definition of services, enabling a use of advanced information about required QoS parameters that may need to be instantiated upon setting up of sessions with user domains 120.